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Tag: wifi

The ESP8266 is an interesting chip, I mentioned it here several times (sorry: mostly german). In a short description, it’s a freely programmable microcontroller. Compared to Arduino & Co., it’s a real number cruncher. The ESP is faster, has more memory, and the best thing: it has builtin WiFi. You’ll find more information all over the network, a basic overview is contained in Wikipedia.

I tested several boards when playing with this chip. Today, I want to describe one that goes with the name Witty Cloud.

Basically, it’s a board with an ESP-12-F, a USB connector that delivers power, a little pushbutton, a LDR (Photoresistor) and a RGB-LED. So there’s plenty of hardware to play with. When you buy the module, you receive a stack of two PCBs. The lower one has a second USB connector, which is equipped with a serial converter. So it’s not only used as a power source, but also as a programming and debugging interface. Furthermore, there’s a reset- and a flash-button on the lower board. After programming, you just need the upper board, and you can even send newer firmware versions to it over the air (OTA).

The lower board is only used for programming

Stacked like this, the module costs less than three Euro, you just need a USB cord and a compiler to start programming. I suggest using the Arduino IDE, it’s very easy to use, even for beginners. After installation of the ESP8266 extensions, it’s best to select WeMos D1-Mini in the board manager, this way everything works fine.

Unfortunately, it’s not easy to find proper documentation for the Witty. So i scribbled the picture above, at first to have some kind of reminder for myself. So the pin labeled GPIO13 is connected to the blue channel of the RGB-LED, in the Arduino environment it’s called D7.

Label

Pin (Arduino)

Purpose

REST

—

Reset

ADC

A0

Analog input, connected to LDR

CH_PD

—

Chip Power-Down

GPIO16

D0

GPIO, freely usable

GPIO14

D5

GPIO, freely usable

GPIO12

D6

GPIO, green channel of RGB-LED

GPIO13

D7

GPIO, blue channel of RGB-LED

VCC

—

+5V power

TXD

TX

Serial interface

RXD

RX

Serial interface

GPIO5

D1

GPIO, freely usable

GPIO4

D2

GPIO, connected to pushbutton

GPIO0

D3

GPIO, connected to flash-button, not really freely usable

GPIO2

D4

GPIO, connected to blue LED on the ESP-Module

GPIO15

D8

GPIO, red channel of RGB-LED

GND

—

Ground

I would be highly interested in a circuit of the board, and if you have any corrections or suggestions: just let me know.